AI Basics with AK

Season 02 - Introduction to Python Programming

Arun Koundinya Parasa

Episode 02

Variables & Data Types

Agenda

• Variables: Foundations of Programming
  • Initializaton & Declaration
  • Reserve KeyWords
  • Updations
• Data Types: DNA of Information
  • Different Data Types
  • Data Type Identification

Initializing & Declaration Variables

Last week we have seen an example of variables declaration i.e.; x=2. However, let us see some basic rules:

• Variables are like characters.
• Variables can contain only Alphabets, Numbers and Underscore
• They are case sensitive.
• They can start with underscore & alphabets but not with digits.

x0 = "Fish"
_x = "2"
x_x = 1203
x = 2
x = y = z = "MultipleAssignment"

Declarations that are not allowed

• 0x = "startingwithzero"
• x-x = "hyphen"
• x x = "space"

Reserve Keywords

help("keywords")

Here is a list of the Python keywords.  Enter any keyword to get more help.

False               class               from                or
None                continue            global              pass
True                def                 if                  raise
and                 del                 import              return
as                  elif                in                  try
assert              else                is                  while
async               except              lambda              with
await               finally             nonlocal            yield
break               for                 not                 

Updating Variables

x =  2
y = "AI"
print(y)
y = x
print(y)

AI
2

Here we can see that the variable y has been assigned the value 2.

x =  2
y = x
print(y)
x = x + 5
print(y)

2
2

Here we can observe that the y variable does not get updated after the addition operation.

Why there is a difference?

Data Types

Name	Type	Examples
Boolean	bool	True, False
Integer	int	1900, 2000, 203
Float	float	10.30, 34.56
Complex	complex	4j, 6j + 5
Text & String	str	"AI", "Basics"
Lists	list	[ 1 , 2, 3, 4 ]
Tuples	tuple	( 3, 4, 5 )
Dictionaries	dict	{'course' : "AI" , 'Subject' : "Python" }
Sets	set	{ 4 , 7, 8 }

Data Type Identification

x1 = "3"
print("Data Type of x1 is :", type(x1))
x2 = 5
print("Data Type of x2 is :", type(x2))
x3 = True
print("Data Type of x3 is :", type(x3))
x4 = 4j + 1
print("Data Type of x4 is :", type(x4))
x5 = 4.3
print("Data Type of x5 is :", type(x5))

Data Type of x1 is : <class 'str'>
Data Type of x2 is : <class 'int'>
Data Type of x3 is : <class 'bool'>
Data Type of x4 is : <class 'complex'>
Data Type of x5 is : <class 'float'>

x6 = [1,3,4]
print("Data Type of x6 is :", type(x6))
x7 = (1,3,4)
print("Data Type of x7 is :", type(x7))
x8 = {1,3,4}
print("Data Type of x8 is :", type(x8))
x9 = {'course' : "AI" , "Subject": "Python"}
print("Data Type of x9 is :", type(x9))

Data Type of x6 is : <class 'list'>
Data Type of x7 is : <class 'tuple'>
Data Type of x8 is : <class 'set'>
Data Type of x9 is : <class 'dict'>

Thank You